The trend to conservation practices in agriculture has lead to the increased utilization of conservation tillage tools such as chisel plows. Chisel plows typically include a frame which is disposed perpendicular to the direction of travel of the draft vehicle wherein an equal number of chisel shovels are attached to the frame on both sides of the hitch.
Attachments are currently available which allow the use of chisel shovels in place of conventional moldboard plow bottoms on a moldboard plow frame. These attachments allow for multi-purpose use of moldboard plow frames which results in lower overall equipment costs. However, the use of such an attachment results in a different line of force than that encountered with the use of moldboard bottoms. Since the conventional moldboard plow frame is disposed at an angle to the direction of travel and offset to one side of the draft vehicle hitch, use of chisel shovel attachments with a moldboard plow frame can result in overcutting or undercutting which affects the functional performance of the entire unit. Overcutting is most likely in moldboard frames for smaller on-land machines where the line of force generated by the chisel shovel attachment tends to move the frame toward a position perpendicular to the direction of travel to increase the working width of the unit. Undercutting is most likely to occur in moldboard frames for larger in-furrow machines where the forces tend to move the frame toward a fore-and-aft orientation with respect to the direction of travel to decrease the working width of the unit.
Attempts to overcome the problems of overcutting and undercutting include the use of a pre-opening coulter positioned forward of the chisel shovels and locked against pivoting from a fore-and-aft orientation. This approach, however, has met with only limited success.
Those concerned with these and other problems recognize the need for an improved chisel plow.